Light coupling element and assembly

Abstract

A light coupling element including a groove and a light redirecting member is described. The groove is for receiving and aligning an optical waveguide and incudes an open front end and a back end. The light redirecting member includes an input side for receiving light from an optical waveguide received and supported in the groove and a light redirecting side for changing a direction of light received from the input side. The groove may include a bottom surface extending between the front and back ends of the groove and including a raised bottom surface portion raised upwardly relative to an unraised bottom surface portion. The unraised bottom surface portion of the bottom surface may be disposed between the raised bottom surface portion of the bottom surface and the input side of the light redirecting member. Optical coupling assemblies including the light coupling element and an optical waveguide are described.

What is claimed is: 
     
       1. A light coupling element comprising,
 a groove for receiving and aligning an optical waveguide and comprising an open front end and a back end; and 
 a light redirecting member comprising:
 an input side for receiving light from an optical waveguide received and supported in the groove; and 
 
 a light redirecting side for changing a direction of light received from the input side, wherein the groove comprises a bottom surface extending between the front and back ends of the groove and comprising a raised bottom surface portion raised upwardly relative to an unraised bottom surface portion, the unraised bottom surface portion of the bottom surface disposed between the raised bottom surface portion of the bottom surface and the input side of the light redirecting member, wherein the raised bottom surface portion comprises first and second spaced apart raised portions raised upwardly relative to a portion of the bottom surface disposed between the first and second spaced apart raised portions. 
 
     
     
       2. The light coupling element of  claim 1 , wherein when an optical waveguide is received in and supported by the groove, a bottom-most portion of the optical waveguide along a first segment of the optical waveguide rests on and makes physical contact with the bottom surface, and a bottom-most portion of the optical waveguide along a different second segment of the optical waveguide is disposed above the bottom surface defining a gap therebetween. 
     
     
       3. The light coupling element of  claim 1 , wherein the unraised portion of the bottom surface extends from the raised portion of the bottom surface to the input side of the light redirecting member. 
     
     
       4. An optical coupling assembly comprising:
 a light coupling element comprising:
 a groove for receiving and aligning an optical waveguide and comprising an open front end, a back end, and a bottom surface extending between the front and back ends of the groove; 
 a light redirecting member comprising:
 an input side for receiving light from an optical waveguide received and supported in the groove; and 
 a light redirecting side for changing a direction of light received from the input side; and 
 
 
 an optical waveguide received in and supported by the groove, the optical waveguide having an end face at or near the input side of the light redirecting member, the optical waveguide comprising adjacent first and second segments, the second segment disposed between the first segment and the input side of the light redirecting member and comprising the end face of the optical waveguide, such that a bottom-most portion of the optical waveguide along the first segment of the optical waveguide rests on and makes physical contact with the bottom surface of the groove, and a bottom-most portion of the optical waveguide along the second segment of the optical waveguide is spaced part form the bottom surface defining a gap therebetween, wherein the groove comprises first and second pinched regions spaced apart from each other along a first direction from the front end to the back end and defining a third region therebetween, such that a minimum width of the groove in each of the first and second pinched regions is less than a minimum width of the groove in the third region. 
 
     
     
       5. A light coupling element comprising:
 a groove for receiving and aligning an optical waveguide and comprising an open front end and a back end; and 
 a light redirecting member comprising:
 an input side for receiving light from an optical waveguide received and supported in the groove; and 
 
 a light redirecting side for changing a direction of light received from the input side, wherein the groove comprises a bottom surface extending between the front and back ends of the groove and comprising a raised bottom surface portion raised upwardly relative to an unraised bottom surface portion, the unraised bottom surface portion of the bottom surface disposed between the raised bottom surface portion of the bottom surface and the input side of the light redirecting member, wherein the groove extends along a first direction and comprises: 
 a first pinched region disposed between, and spaced apart from, the front and back ends of the groove; and 
 a support region disposed between the front end of the groove and the first pinched region, a minimum width of the groove in the first pinched region being less than a minimum width of the groove in the support region. 
 
     
     
       6. A light coupling element comprising:
 an attachment area for receiving and permanently attaching to an optical fiber; 
 a light redirecting member extending from the attachment area and comprising:
 an input side for receiving light from an optical fiber disposed at the attachment area; 
 a light redirecting side for receiving light from the input side and changing a direction of the light received from the input side; and 
 a groove formed in the attachment area for receiving an optical fiber and extending in a first direction from an entrance end to an opposite terminal end proximate the input side of the light redirecting member, the groove comprising:
 a bottom surface and opposing sidewalls extending upwardly from opposite lateral sides of the bottom surface and defining a width of the groove and an open top; 
 a stop region proximate the input side of the light redirecting member; 
 a centering region adjacent the stop region opposite the input side of the light redirecting member; and 
 a support region between the entrance end and the centering region, the width of the groove in at least a portion of the centering region and in at least a portion of the stop region being less than the width of the groove in at least a portion of the support region, 
 
 
 wherein the width of the groove in the centering region decreases in the first direction at a first rate and the width of the groove in at least a portion of the stop region decreases in the first direction at a second rate greater than the first rate. 
 
     
     
       7. The light coupling element of  claim 6 , such that when an optical fiber having an average diameter D is received and supported in the groove, the width of the groove in at least a portion of the stop region is less than D. 
     
     
       8. The light coupling element of  claim 6 , such that when an optical fiber having an average diameter D is received and supported in the groove, a minimum width of the groove in the support region is in a range of D to 1.1D, and a minimum width of the groove in the stop region is less than about 0.8D. 
     
     
       9. The light coupling element of  claim 8 , wherein when an optical fiber is received and supported in the groove, the optical fiber touches, at most, one of the sidewalls in the first pinched region. 
     
     
       10. The light coupling element of  claim 6 , wherein the groove further comprises a first pinched region disposed between the support region and the centering region, a minimum width of the groove in the first pinched region being less than a minimum width of the groove in the support region. 
     
     
       11. The light coupling element of  claim 6 , wherein when an optical fiber is received and supported in the groove, the optical fiber touches both of the sidewalls in the stop region. 
     
     
       12. An optical coupling assembly comprising:
 a light coupling element comprising:
 a groove for receiving and aligning an optical waveguide and comprising an open front end, a back end, and a bottom surface extending between the front and back ends of the groove; 
 a light redirecting member comprising:
 an input side for receiving light from an optical waveguide received and supported in the groove, and 
 a light redirecting side for changing a direction of light received from the input side; and 
 
 
 an optical waveguide received in and supported by the groove, the optical waveguide having an end face at or near the input side of the light redirecting member, the optical waveguide comprising adjacent first and second segments, the second segment disposed between the first segment and the input side of the light redirecting member and comprising the end face of the optical waveguide, such that a bottom-most portion of the optical waveguide along the first segment of the optical waveguide rests on and makes physical contact with the bottom surface of the groove, and a bottom-most portion of the optical waveguide along the second segment of the optical waveguide is spaced part from the bottom surface defining a gap therebetween, wherein the groove further comprises: 
 a stop region proximate the input side of the light redirecting member; 
 a centering region adjacent the stop region opposite the input side of the light redirecting member; and 
 a support region between the front end and the centering region, the width of the groove in at least a portion of the centering region and in at least a portion of the stop region being less than the width of the groove in at least a portion of the support region, 
 wherein the width of the groove in the centering region decreases in a first direction from the front end to the back end at a first rate and the width of the groove in at least a portion of the stop region decreases in the first direction at a second rate greater than the first rate. 
 
     
     
       13. The optical coupling assembly of  claim 12 , wherein the groove is a first groove in a plurality of substantially parallel grooves extending in a first direction and arranged in an orthogonal second direction, and the optical waveguide is a first optical waveguide in a plurality of optical waveguides, each optical waveguide in the plurality of optical waveguides received in and supported by a corresponding groove in the plurality of grooves. 
     
     
       14. The optical coupling assembly of  claim 12 , wherein the first segment of the optical waveguide has a first diameter, and the end face has a second diameter greater than the first diameter. 
     
     
       15. The optical coupling assembly of  claim 12 , wherein the bottom surface comprises a raised bottom surface portion raised upwardly relative to an unraised bottom surface portion, the unraised bottom surface portion of the bottom surface disposed between the raised bottom surface portion of the bottom surface and the input side of the light redirecting member.